1. Field of the Invention
The present invention relates to a parallel folding device of a folding machine which can switch folding specifications and delivery modes for parallel folding operations at the same time.
2. Description of the Related Art
A web rotary printing press includes a folding machine which cuts, by a predetermined length, a web which has been dried and cooled after a printing operation, and which folds the web in the width direction or in the length direction.
There have been various structures for this type of folding machine. A folding machine including a parallel folding device, for example, as shown in FIG. 12 has been known (see Japanese Patent Laid-open Official Gazette No. 2002-60128).
This folding machine is provided with a parallel folding device 1 in a direction which makes a web W progress. The web W has been dried and cooled after a printing operation, and is guided into a paper inserting part of the folding machine. The parallel folding device 1 cuts and folds the web W by a predetermined dimension. The parallel folding device 1 includes a cutting cylinder 2, a folding cylinder 3 and a first jaw cylinder 4, all of which rotate in a direction as shown by an arrow in the figure.
The web W which has been sent into a space between the cutting cylinder 2 and the folding cylinder 3 is cut with a cutting blade, which is not illustrated, of the cutting cylinder 2 by the predetermined dimension. In addition, the web W is held with a pin, which is not illustrated, of the folding cylinder 3, and thereby is caused to wrap around a lower circumferential surface of the folding cylinder 3. The web thus cut, which is held with the pin, is subsequently gripped with gripper boards 5a to 5d of the first jaw cylinder 4 in cooperation with a sucker blade, which is not illustrated, of the folding cylinder (a number of gripper boards are provided in axis directions respectively of gripper board shafts 6a to 6d arranged in positions which quarter the circumferential surface). The cut web thus gripped is turned into a signature while being half-folded, and is caused to wrap around, and contact, the upper circumferential surface.
An upper second jaw cylinder 7 and a lower second jaw cylinder 8 are caused to be opposed to, and in contact with, each other downstream of the first jaw cylinder 4. An upper chopper folding device 9 is provided downstream of the upper second jaw cylinder 7. A lower chopper folding device 10 is provided downstream of the lower second jaw cylinder 8.
A number of gripper devices (hereinafter referred to as “grippers”) 12a to 12d are provided in axis directions respectively of gripper shafts 11a to 11d arranged in positions which quarter the circumferential surface of the upper second jaw cylinder 7. A number of gripper devices (hereinafter referred to as “grippers”) 14b and 14d are provided in axis directions respectively of gripper shafts 13b and 13d arranged in positions which bisect the circumferential surface of the lower second jaw cylinder 8. The grippers 12a to 12d of the upper second jaw cylinder 7 are sequentially caused to be opposed respectively to the gripper boards 5a to 5d of the first jaw cylinder 4. The grippers 14b and 14d of the lower second jaw cylinder 8 are designed to be opposed to only the gripper boards 5b and 5d of the first jaw cylinder 4 respectively. Incidentally, in FIG. 12, reference numeral 15 denotes a fan wheel for a delivering operation; and 16, a conveyer for the delivering operation.
In addition, the first jaw cylinder 4 is provided with a cam mechanism, which is not illustrated. A gripper opening cam causes the gripper boards 5b and 5d of the first jaw cylinder to open, the gripper boards 5b and 5d being assigned for the lower second jaw cylinder 8. If a phase of the gripper opening cam is changed or switched, the cam mechanism causes the gripper boards 5a to 5d to operate in a position which makes the folding cylinder 3 and the first jaw cylinder 4 opposed to, and in contact with, each other, and thereby causes the first jaw cylinder 4 to hold the signatures which have been transferred one by one. Thereafter, the cam mechanism can switch delivery operations between what is called an upper combined delivery and what is called an upper and lower distribution delivery. The upper combined delivery transfers the signatures from the gripper boards 5a to 5d of the first jaw cylinder 4 to only the grippers 12a to 12d of the upper second jaw cylinder 7. The upper-and-lower distribution delivery transfers the signatures from the gripper boards 5a to 5d of the first jaw cylinder 4 to the grippers 12a and 12c of the upper second jaw cylinder 7 as well as the grippers 14b and 14d of the lower second jaw cylinder 8.
Although the parallel folding device of the folding machine as disclosed in Japanese Patent Laid-open Official Gazette No. 2002-60128 can switch delivery operations between the upper combined delivery and the upper and lower distribution delivery, however, the parallel folding device of the folding machine has a disadvantage of being unable to switch folding operations between the following two folding specifications, since the gripper opening cam for opening the gripper boards 5a and 5c of the first jaw cylinder 4 for the upper second jaw cylinder 7 is fixed, or for similar reasons. One of the two folding specifications is a folding specification (a double folding and a delta folding) to fold the signatures between the first jaw cylinder 4 and the upper second jaw cylinder 7 and/or between the first jaw cylinder 4 and the lower second jaw cylinder 8 after a parallel folding operation. The other of the two folding specifications is a folding specification (a single folding) to fold no signature between the first jaw cylinder 4 and the upper second jaw cylinder 7 or between the first jaw cylinder 4 and the lower second jaw cylinder 8 after the parallel folding operation.